The review aimed to determine the possible positive or negative effects of oral or parenteral vitamin C supplementation on homeostasis processes in the organism. Vitamin C is commonly used in different sectors, such as cosmetics and raw materials, especially in the food and beverage sector. In addition, individual use of vitamin C supplements has increased in recent years, especially for disease prevention and alleviation. This led to individuals consuming excessive amounts of easily accessible vitamin C. As a result, vitamin C supplements are known to be safe for physiological systems, but high levels of parenteral and oral vitamin C supplements can significantly disrupt physiological balance. In the organism, sodium-dependent vitamin C transporters (SVCT1) and (SVCT2) play a major role in vitamin C homeostasis. Oral or intravenous vitamin C supplements can produce significantly different serum and plasma vitamin C concentrations. Therefore, it is important to know the appropriate dose range of oral and parenteral vitamin C supplementation in terms of vitamin C homeostasis in the organism. To prepare this review, I researched published scientific literature by using the following keywords: “ascorbic acid,” “vitamin C,” “homeostasis,” “dosage,” and “health.” This search was carried out from the electronic databases in the Web of Science, PubMed, and Google Scholar databases, and 46 eligible studies were included from the past 28 years in English and Turkish. In addition, this review article provides information on the administration and daily dosages of oral and parenteral vitamin C supplements needed in individuals to prevent vitamin C deficiency.